Improved brick



UNITED STATES PATENT iEEICE.

DAVID L. BARTLETT AND GEORGE H. JOHNSON, OF BALTIMORE, MARYLAND.

IMPROVED BRICK.

Specification forming part of Letters Patent No. 57,46] dated August 28, 1866.

To all whom it may concern:

Be it known that we, DAVID L. BARTLETT and GEORGE H. JOHNSON, of Baltimore, in the county of Baltimore and State of Maryland, have invented a new and Improved Brick 5 and we do hereby declare the following to be a full and exact description thereof, reference being had to the accompanying drawings, forming a part of this speciiication, in which- Figure 1 is a perspective view of one of our improved bricks; Fig. 2. a central vertical section through a wall constructed of the bricks; Fig. 3, a plan view of a section of eircular wall built of the same.

Similar letters indicate like parts in all ot' the figures.

The nature ot our invention consists in molding bricks with bosses upon one side thereof', and corresponding recesses upon the other, said bosses and their counterpart recesses being iormed in a line centrally between the sides and at points each equidistant from the center and ends, respectively, ot' the bricks.

Our improved bricks may be made of any desirable material, or combination ot' 1naterials, worked, tempered, and prepared in any suitable manner.

The desired material, when properly prepared, is fashioned in molds so shaped and constructed as to produce bricks, A, having two bosses or projections, b 1),(whicl1, by pret'- erence, we make semi-spherical in form,) formed upon one face thereof, and concavities or recesses c c, Fig. 2, immediately opposite thereto in the other. These bosses and concavities are formed, respectively, at each end of the brick, each at a point removed from the end a distance equal to about one-fourth of the length of the brick, or midway between the center and the end, and centrally also between the side thereof. Consequently, the distances between the bosses, in a course of bricks laid end to end or side by side, will always be the same, and the bricks will always tie and interlock, whether superimposed longitudinally or transversely in breaking joints.

Where additional strength is required in the wall we add a boss cent-rally to the end of each brick, and form a corresponding concavity at the other.

We contemplate molding our embossed bricks into segmental lforms for the construction of cylindrical walls, placing the bosses and concavities, as described, midway between the center and ends and cenrall y between the sides; but for all ordinary purposes circular walls may be constructed with our rectangular bricks, which will interlock when laid upon a curve, as illustratedin Fig. 3 of the drawlngs.

Ve are aware that a patent was granted to Levy Till in 1855 for bricks made with double conical spurs on one side and extended grooves in the other; and we disclaim bricks so formed, having two series of spurs and channels or grooves arranged in parallel rolls upon the opposite faces thereof. Such bricks are. not only more expensive and more liable to fracture than ours, but admit ot being laid in straight lines only.

Havingt'ull y described our own invention, we claim as new and desire to secure by Letters Patent- A brick having bosses projecting from one face thereof, and counterpart recesses formed in its opposite face, each at a point midway bctween the sides, center, and end of the brick, substantially in the manner and for the pun pose herein setforth.l

The foregoing specification of our improved bricks signed by us this 19th day of June, A. D. 1866.

D. L. BARTLETT. eno. H. JOHNSON.

In presence of- CHARLEs PORTER, ROBERT CULNAN. 

